Extraction of oil by volatile solvents



A. W. MACILWMNE AND G. F. HOLDCROFT. EXTRACTION OF OIL BY VOLATILESOLVENTS. APPLICATION FILED AUG.8. I919.

LAW 8&2 Patented Mar. 28,1922.

//v VEN TORS EXTRACTION OF OIL BY VOJDATILE SOLVENTS.

Specification of Letters Patent. Patented Mam-"28, I922.

Application filed August 8, 1919. Serial Ito. 316,214.

To all whom it may concern:

Be it known that we, ALFRED WILLIAM MAoILwArNE, a subject of the King ofGreat Britain and Ireland, residing at Manor House, North Ferri-by, inthe East Riding of Yorkshire, England, and Gnoncn FRED ERICK HoLnoRoF'r,a subject of the King of Great Britain and Ireland, residing at Yeovil,North F erriby, aforesaid, have invented new and useful Improvements inthe Extraction of Oil by Volatile Solvents, of which the following is aspecification.

This invention relates to an improved process for the extraction, bymeans of volatile solvents, of oil from seed or other oilyieldinmaterials.

Usua ly, in. carrying out the process, of extraction the preparedmaterial is charged into an extractor or closed vessel fitted withstirrers and a perforated false bottom. Solvent, consisting of benzolineor other suitable volatile liquid, is run in until the charge iscovered; the charge is then washed b running in fresh solvent anddrawing. 0 the oil-charged solvent; the washing being continued untilthe oil in the charge is judged to, be sufficiently reduced.

The washin is now stopped, and the solvent allowe .to drain away;leaving the charge still saturated with solvent which holds oil insolution. IJive steam is then driven through the solvent saturatedcharge; the steam evaporating the solvent, which is recovered bcondensation.

It is found thatthls, the ordinary; process of extraction is attended bycertain disadvantages, amongst which the following may be mentioned 1.The solvent contained in the charge after draining has oil in solution.When the solvent is evaporated, the oil, being nonvolatile, remains inthe residue and isnot recovered.

2. Thegreater the quantity of solvent evaporated and the longer thesolvent, present in the charge, is subjected to steam treat- I ment, thegreater-the loss of solvent.-

3. The greater the quantity of solvent left in the charge after drainin,the greater the quantity of steam require to !evaporate it and thegreater the extent of heating required to dry the meal or resldue.

Our invention in a large measure overcomes these disadvantages, andconsists in subjecting the charge, after it has been washed and drainedbut while still saturated with solvent, to hydraulic or other pressure.The pressure is maintained until the expression of the solvent and oilin so lution therein is judged to be sufliciently effected and until themass assumes a comparatively solid condition. In thus pressing thecharge, we expel from it the major portion of the solvent; the lattercarrying with it the oil held in solution. The "charge thus;

compressed is again reduced to a mealy or porous condltlon; whereuponthe solvent not already expressed is recovered by means of steam and bycondensation in the usual I manner.

action of steam, less loss of solvent takes place.

Apparatus adapted for use in carrying our invention into effect isillustrated diagrammatically in the accompanying drawmg. The operationof extracting and compressing may be conducted int e same vessel or 1nseparate vessels. In the present illustration, these operations areconducted in separate vessels; A representing the extractor, and D thecompressor. B is an intermediate container for the reception of thesolvent-charged meal discharged from'the extracting vessel A, pendinits. deliveryto the compressing chamber The solventcharged meal escapingfrom the intermediate vessel B, orfro A as the case may be, is receivedin a closed hopper C, at the base of which is arran d feed apparatuscomprising a horizonta y sliding box C actuated by-a hydraulic cylinderO or other suitable means, with the object of conveyin its contents,received from the hopper O, and discharging the same directly above thehydraulic press I). In co-operation with the feed-box .Cis' a coverplate C which serves to close the bottom ofthe hopper O when'the box Cis advanced as abovefdescribed. The hydraulic press D is or may be of atype commonly the extracting vessel 5 barrel is arranged a horizontallysliding plate D one portion of which is solid, whilst in the otherportion is formed an orifice which corresponds in diameter with that ofthe plunger D The upper face of the sliding plate D is provided with atoothed rack which meshes witha pinion D"; the

latter being fast upon the spindle of a handwheel D.

The action of the apparatus is as follows :The orifice in the slidingplate D V being over the cylinder'or barrel of the press D and theplunger D? being at the bottom 7 thereof, the to and 'fro action of thefeedbox 0 proceeds lmtil the barrel is fully charged. The sliding plateD is then moved so as to bring its solid portion above the barrel,thereby closing its upper end. The plun er then rises and compresses themass, there y expelling the oil-charged solvent; the latter escapingthrough the sides of the barrel and being drained away by the pipe d atthe bottom of the casing d. The sliding plate D is'now restored to itsprevious position and the plunger D further raised so asto bring thecompressed charge of meal into the path of the sliding box G which, .atits next forward movement, pushes the compressed charge of meal off theplungEr D and causes it tofall into the hopper The pressure beneath theplunger D being thereupon released, the latter again descends to thebottom of the barrel, and the feeding action of the box C isresumed .Atthe base of the ho perfE, is arrange breaking apparatus 0 anyappropriate type; as, for example, a pair of wheels E revolving inopposite directions and furnished with saw or other teeth. The state inwhich the meal reaches this apparatus 5 may be described as compact but1s neverh. Im-

theless capable of being readily reduced to a mealy condition.

Upon leavin the chamber of the breaking apparatus the meal passes, byway ofa closed hopper F, to a perforated cylinder F -furnished with asteam-jacket and internally provided with a feed-screw and agitator Ffor conveying the meal longitudinally from beneath thehopper F to theopposite end of the cylinder F and there discharging it to thesteam-jacketed dry-i ing cylinder G, furnished with an agitatingfeed-screw G During the passage of the meal through this cylinder, itbecomes thoroughly dried, andis ultimately discharged past the loadedflap G The outlets from the vessels A, B and E, are respectivelyfurnished with valves A E E for controlling the passage of the materialunder treatment.

The intermediate container B, as also the steaming and drying cylindersF and G are connected with an air-pump or other exhauster with a view tothe withdrawal of solvent-charged vapour and the recovery of the solventbyconden sation.

It will be observed that the whole of the operations described areconducted without exposin the material to the atmosphere.

We c aim A process for the extraction of oil by volatile solvents,consisting in treatin the oilyielding material in an extractor wlth asuit able solvent such as benzoline, and, when sufficiently washed,draining of the oilbearing solvent, subjecting the meal without.exposure to the atmosphere to pressure, breaking up the compressed massso as to re store it to a mealy condition, and then treating it withsteam forthe purpose of removing and recovering the residual solvent,substantially as set forth.

Aim-.0 .waum alumnae; cl-zoncri momma 110mm,

